A reader wrote to tell us he loves Microsoft’s free anti-virus software, “Microsoft Security Essentials,” and has been using it for years. But it doesn’t come on his daughter-in-law’s Windows 8 machine; Windows 8 comes with “Microsoft Defender,” which is only part of Security Essentials. So we recommended switching to Avast, which is free from Avast.com.

Some things to look out for in getting Avast for free: During set-up, you should click “register” and then choose the free version. At another point during registration, you should click on “basic” as your choice, in order to avoid getting simply a free trial of the paid version. Also: under “settings,” uncheck the boxes that allow the program to bombard you with messages; also change the default setting (which provides no updates) so that you get automatic updates. (Who would want to do them manually: only the programmer who wrote the code.)

By the way, we use Avast Mobile Security for Android phones, to stop malware, spyware and viruses. They say it also stops the prying eyes of a suspicious partner.